package datastructures.hashmap;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;

public class ContaFrequenza {

		 public static void main(String[] args) {
		 
			List<String> list = new ArrayList<String>();
			list.add("a");
			list.add("b");
			list.add("c");
			list.add("d");
			list.add("b");
			list.add("c");
			list.add("a");
			list.add("a");
			list.add("a");
		 
			System.out.println("\nExample 1 - Count 'a' with frequency");
			System.out.println("a : " + Collections.frequency(list, "a"));
		 
			System.out.println("\nExample 2 - Count all with frequency");
			Set<String> uniqueSet = new HashSet<String>(list);
			for (String temp : uniqueSet) {
			System.out.println(temp + ": " + Collections.frequency(list, temp));
			}
		 
			System.out.println("\nExample 3 - Count all with Map");
			Map<String, Integer> map = new HashMap<String, Integer>();
		 
			for (String temp : list) {
				Integer count = map.get(temp);
				map.put(temp, (count == null) ? 1 : count + 1);
			}
			printMap(map);
		 
			System.out.println("\nSorted Map");
			Map<String, Integer> treeMap = new TreeMap<String, Integer>(map);
			printMap(treeMap);
		 
		  }
		 
		  public static void printMap(Map<String, Integer> map){
		 
			for (Map.Entry<String, Integer> entry : map.entrySet()) {
				System.out.println("Key : " + entry.getKey() + " Value : "
					+ entry.getValue());
			}
		 
		  }
		 
		}
